些 sets 此 (this) over 二 (two): 'this' multiplied — some, several. A quantity word built from pointing at things more than once.
些 softens numbers into estimates: 一些 (some), 这些 (these — with 这), 那些 (those — with 那), 有些 (some of them / somewhat). Chinese loves not committing to exact counts; 买一些水果 ('buy some fruit') is warmer than a precise 买五个. Learn 些 and you can shop, complain (好一些, a bit better) and generalize like a native.
This 此 times two 二 — not one thing but SOME.
好一些 'better by some' — Chinese comparisons often improve in vague, polite increments rather than exact amounts.